CD8A and neoplasm: Recently, several CRISPR/Cas9-mediated genetic screening studies have revealed that the loss of certain pro-survival components such as HOIP, HOIL, TBK1, IKKβ or c-FLIP in TNFα signaling would sensitize tumor cells to CD8+ T cell- and NK cell-mediated killing [59–62]; in contrast, the loss of TNFR1, caspase-8 or FADD protects tumor cells against CD8+ T cell and NK cell cytotoxicity [62–64].